sysdeps/pthread/call_once.c

   1 /* C11 threads call once implementation.
   2    Copyright (C) 2018-2024 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <stdalign.h>
  20 #include <shlib-compat.h>
  21
  22 #include "thrd_priv.h"
  23
  24 void
  25 __call_once (once_flag *flag, void (*func)(void))
  26 {
  27   _Static_assert (sizeof (once_flag) == sizeof (pthread_once_t),
  28                   "sizeof (once_flag) != sizeof (pthread_once_t)");
  29   _Static_assert (alignof (once_flag) == alignof (pthread_once_t),
  30                   "alignof (once_flag) != alignof (pthread_once_t)");
  31   __pthread_once ((pthread_once_t *) flag, func);
  32 }
  33 #if PTHREAD_IN_LIBC
  34 versioned_symbol (libc, __call_once, call_once, GLIBC_2_34);
  35 # if OTHER_SHLIB_COMPAT (libpthread, GLIBC_2_28, GLIBC_2_34)
  36 compat_symbol (libpthread, __call_once, call_once, GLIBC_2_28);
  37 # endif
  38 #else /* !PTHREAD_IN_LIBC */
  39 strong_alias (__call_once, call_once)
  40 #endif